Renewable and non-polluting sources of energy are currently in high demand. Traditional sources of generating energy such as the combustion of fossil fuels, including coal, natural gas and oil, are becoming less and less favored due to their environmental disadvantages. The combustion of coal, oil or gas generates large quantities of carbon dioxide, oxides of sulfur and nitrogen, and other pollutant gases, which may contribute to global warming, acid rain, air pollution and a number of other environment and health damaging effects. World reserves of coal, oil and natural gas are also thought to be relatively low, and may run out in the foreseeable future.
Other sources of energy include nuclear fission, whereby atoms of radioactive elements are bombarded with a neutron source, which splits the radioactive element into an element or elements of smaller atomic mass, generating massive quantities of energy in the process. Unfortunately, the use of radioactive materials means that environmentally safe methods of disposal of waste are difficult to achieve. The radioactive waste generated is commonly stored in sealed containers and then buried in restricted access landfill sites or dumped at sea. There have been many occurrences of radioactive waste leaking from these containers and damaging the local environment. The damage caused by radioactive waste may be irreversible and the radiation generated by the waste may last decades.
Thus, there is a strong desire to produce non-polluting and renewable energy sources. Known non-polluting and renewable energy resources include tidal-powered electricity generators, and wind-powered electricity generators. These types of generators generally employ turbine blades extending from a central hub, and which blades are designed to translate the linear motion of wind or tidal water into rotational motion of the central hub, which is connected to a suitable energy generator. Known generators of this type generally employ turbine blades which are rigidly fixed to the central hub and are orientated such that leading blades are aerodynamically configured in the optimal position to convert fluid linear motion into rotational motion. However, this configuration of fixed blades means that trailing blades are not optimally configured to reduce drag and thus prevent the maximum amount of linear to rotational motion available to generators. Thus the optimal conversion of linear to rotational motion may not be achieved using these known systems, and consequently, optimal energy generation is not possible.
It is an aim of preferred embodiments of the present invention to overcome or mitigate at least some of the disadvantages of the prior art systems described above, or other disadvantages, whether described above or not.